A corpokatioh



Nov. 17, 1925.

W. K. HOWE AUTOMATIC TRAIN CONTROL SYSTEM Original Filed Feb. 5, 1915 INVENTDR I X BY 5. ATTORNEY WITNESSES.-

Patented Nov. 17, 1925.

wmezmos K. HOWE; on semeste s, new 1031:, assesseear-game AITTGIv'IAT-IG TRAIN-centurion sns'rnirj- Applicationfilesl February 5, 1915," Serial Nb. ears. Re ewed? October. 2,1920; seriarno. 412337.

To (plZrwho mitm-ag conoerm' 7 Be known that L VVm rnnor K. HOWE,

a citizen oi the United States, and a resident of the city of Rochester, in the, county. of

Monroe and State of New York, have in Vented-new and useful Improvements 1n, Au;

tomatic- Train-Control- Systems, of which the following-is a specification. 7 j This invention relates to ani automatic train control system;

The primary object of? this invention is; a construction and arrangenient whereby. the movement of a' 1110YableVGhlCl6 on a trackmay-he coiitrolleclby means other than by an application of the Well known emer,=-

gency brake and also" in addition hy; {tnapplicationof the Well known emergency bral ze or'an apparatus hayingsimilareitectsupon the train. C p v Other objects and advantages will appear as the description of the invention pro-' gresses, and the novel featuresv-cfthe in-,

vention' Will be particularly pointed out in the appendedfclaims. I p j 1 v In describing the invention in'jdetailtrefere'nce ishadto the accompanying drawing-, comprising a single figure' which is asche maticillustrationof a2 railway track Witha;

car thereon,,equippedwith traincontrolliiigr. I j j y .the-relays 6,. 7 andfi respectivelyu- Que ter 1 and 2 -designate the; two. rails; of av rail; 3 Way track, oneofi which is shown ,as divided} into sections by means of the Well known in sul atinig joints 8. At points close totthje; i.n-' sulating jcintssourcesj of current, asiando, are connected-acrossthe rails oijthe trace 1 way,- and on the other side otthe insulat-t ing joints are connected translating devices,; as 6, 7 and 8 The dividing of one railof: the track by insulating joints andconneict ing'a source of'currentacross the rails of one point between two joints and a rjelayrat: another point hetWeenthe-sa-me two joints; forms'the Well known track'circuit section,; so that the railway is thereby divided iutoa closed circuited track circuit seetionsg'whichi areperfectly familiar to and thoroughly understood by those skilled in theartof railway signalling The sources of currentza-re' herein shown as the secondaries. ofrtrans-I formers, of which'the priinariesqare 9 and; 10, which are connected across the two line Wires, 1 2 and 11, whicheictend tlleglength Y th'e,, trackway and; which. areconnected Opposite each insulating oil 1t i is ramp,. as g 14 15 and I6, the greater portion of theramp being-inadvance of-the insulat ns joi inh dir ct on ffie; w i hri in' the direction ofthe arrowri ior'apur- .At about the l c t on it-each rampz s iwsi en d a tr ns orms, o wh ch hetp i-c m r s wd' g i cbyt 1,7,1'11t8i nd 19, Which are each, connected. across thei line ir and l 'achi f-t eprim s h 8.: and 191 .5. a tse n arn med iix i three pa-rtsj that is the primary? 17 v hasf ifqh e' secon dary, formed of. thethree parts",- 20 '21 and! the nr-imary ISjhaS a second ry Q fl fid; or the three parts, 23; 24; and' 25.; ,and;the

primary 19 has a secondanyiormed; of. the

- P e t ers na f n n e.- u y exp a n minalio f'ithe.seconda ryportions21, 24:; and 2,71 4

329T: 1 M1 0 aninely r m points operatiye 1 relationith the tarinatures 35, 36 W12 it t ve rt f th r ay 6, n 81- esne tire in eate minaLefhe e n ry" portions 22, 25 and 28 isw-conneoted to one terminal of; the; secondary portions 21, "24 and 27; respectively, and v the-other; terminal 1 of the secondary; portions 22 2.5;andi 2 8 is? connected by means of the Wires 4:1,A25, and. 43,, respectively to front points in operative relation withthe armaturesl, 4 5 and 46;: resp ctively of the; relays?6,-7 and 8,"resp ec-" tivelyf u 1 C r n or 16,1 cau e #110: flow; thr ugh; circuit controllers 47, 148* 49 respectively,which1 are normally in theclosedposition, but may of a suitable insulating material.

be opened by any desired or appropriate means to produce an effect hereinafter more fully described.

A movable vehicle has been herein illustrated as consisting of the wheels and 51 connected by the axle 52, which supports the journal box 53 bearing the side bar 54 which for simplicity is assumed to be made The side bar 54 has a projection 55 by which is supported a shoe 56, which is freely movable vertically in the projection 55, and is caused to move downwardly by reason of the collar 57 rigidly attached to the shoe 56 by means of the spring 58, which is positioned between the collar 57 and the projection 55, but the shoe 56 is prevented from moving too far downwardly by reason of the enlarged upper end 59 which comes in contact with the projection 55 and prevents too great a downward movement of the shoe 56.

The side bar 5-1 also supports three circuit controllers, one of which is composed of the movable pivoted part 60 and the fixed part 61; another of which is composed of the part 62, similar to the part 60; and the part 63, similar to the part 61; the third of which is composed of the part 64, similar to the part 60, and the part 65, similar to the part 61. hen the shoe 56 is at the downward limit of its movement the parts 60, 62 and 6st are moved by gravity, or any appropriate means, into contact with the fixed parts 61, 63 and 65 respectively, but when the shoe 56 is raised by contact with a ramp, as 14, then the parts, 60, 62 and 64 each break contact with the parts, 61, 63 and 65, respectively.

Each movable vehicle is equipped with a relay 66, a relay 67 having two windings thereon, 67 and 67 ,1 relay 68, a relay 69, a means for controlling the movement of the vehicle other than by an emergency application ofthe brakes, 70, and a means, 71, for controlling the movement of the'vehicle by an application of the emergency brake, or similar apparatus.

It is to be understood that emergency brake controlling means 71 may be of any of the well known forms which vent a train line upon deenergization and will not stop venting the train line even if reenergized until the air pressure in the train line has been reduced to a certain value.

0pcrati0n.-Normally, when the vehicle or train is traveling in a track section or block between the ramps at the entranceto.

said blocks and has not approached any train immediately ahead, the relays 67 and 69 are energized, while the relays 66 and 68 are deeneergize'd. The circuit for maintaining the relay 67 normally energized while the train is traveling between ramps under safe proceed conditions, may be traced as follows: one terminal of the battery 81,

' wires 82 and 90, member 63, member 62, wire 91, armature 87, wire 92, coil 67 and wires 93 and 86 to the other terminal of the battery 81.

When the relay 67 is energized and its armature 89 is in the upper position, the train controlling mechanism is energized by a circuit which may be readily traced on the drawing so that this controlling mechanism will have no effect upon the movement of the vehicle, other than to impose such limitations on its speed or its movement in other respects as may be found expedient even when the vehicle is traveling under safe proceed conditions, all depending upon the particular character and functions of the mechanism 70.

The circuit for normally energizing the relay 69 when the vehicle is traveling between ramps may betraced as follows: one terminal of the battery 111, wire 112, member 60, member 61, wire 113, relay 69, wire 114 armature 98 and wire 115 to the other terminal of the battery 111.

Current flowing in the above traced circuit which maintains the relay 69 energized and its armature 99 in the upper position, as shown, completes a circuit for energizing the emergency brake controlling apparatus 71 which may be traced as follows: one terminal of the source of current 100, wires 101 and 102, armature 99, wires 103 and 104, emergency brake controlling apparatus 71 and wire 105 to the other terminal of the battery 100. The energization of the emergency brake controlling apparatus will prevent that apparatus from having any effect upon the movement of the vehicle.

The parts on the vehicle are caused to assume the normal position, hereinbefore described, when the vehicle passes a ramp energized with high voltage, as will be explained more fully hereinafter, and in practicing the-invention, it is contemplated that such an energized ramp will be located at the point where the vehicle commences its trip. In order to make the operation and function of the various parts and circuits more clearly understood, different traflic conditions will be assumed and the operation and circuits established under these difi'erent 1 tact with the ramp 1%, although the first pair I of wheels and axle of the vehicle has not yet passed over the insulating joint 3 into the block or track section to which the track relay 6 isconnected, it being further assumed that no other train occupies either of the next two blocks in advance.

' above traced patn rlssumingthe conditions just described,- when the contact shoe 56 1s 1n COIltZLCtWVltl'i" the ramp l i, a circuit will be formed as follows: One terminal of the secondary portion 22, Wire e1, armature t l, wire 72, circuit controller 47 in the closed position, wire 73, ramp 14, shoe 56, wires 74 and 75, im-

pedance 76, wire 77, relay 66, wires 76 and.

79, journal box 53, axle 52, wheel 50, rail 1, wire-29, secondary portion 520 and secondary portion 21 to the other terminal of secondary portion 22. The high difference of potential created by including all of the secondary portions 20, 21 and 22 in series in the above traced circuit will cause such. a flow of currentthrough the relay even with the impedance 76 in series therewith will cause it to become slu'iiciently energized to raise its armatures, as 80 and 117. The raising of ar- 6 mature S0 to the upper position, as shown, will cause a flow of current through one COIl 67 of the relay 67 in a circuit as follows: One terminal 01": the battery 61, wires 82 and 83, armature 80, wire 84, coil 67 and wires 85 and 86 to the other terminal of the battcry 81. Current flowing in the above traced path will sui'liciently energize the relay 67 as to cause it to maintain in the upper position each of its armatures 87, 88 and 89.

The armature 89 being in its upper position will maintain energised the train controlling mechanism 70 so that it will havcno efiect upon the movement of tie vehicle.

The armature 8'? being held in itsupper position will complete the stick circuit hereinbefore traced for the relay 67 in which'current will flow, as soon as theshoe 56 passes so far down the inclined portion of the ramp Has to allow its upper end 59 to descend such a distance as will allow the movable members 60, 62'and 64 to make contact with the fixed portions 61, 63 and 65 respectively. The contact of shoe 56 with ramp 14 will also cause current to flow at the same time as it commences to flow through relay 66 in wire 72, circuit controller 47- in the closedv position, wire 7 3, ramp 1%, shoe 56, wires 74, 75, 94- and 116, armature 11?, in its lower position, ires 1.18 and 96, relay 68, wires 97 and 79, journal box 53, axle 52, wheel 50, wire 29, secondary portion 20 and secondary portion 21 to the other terminal of the secondary portion 22. Current flowing in the b will sui'iiciently energize relay 68 to maintain its armatures 98-and 99' raised to the upper position, as shown,

The armatureQQbeing in the upper position, as shown, will complete the circuit hereinbetore traced for energizing the emergency brake controlling apparatus 71 The emergency brake controlling apparatus 7 1 is not only energized by the circuit here'iubetore traced, but 18 also energized by a circuit which is closed only wliii'le the shoe- 56 is in or nearitslower p'ositionythat is, when it is in such a position that thecircuit controllers controlled therebyare in: the closed position, which circuit is as follows: ?0

One terminaloi' the battery 100,:wircs10l;

and 106, member 64, member. 65, wires 107K and 16s, emergency bralie controlling ape pa-ratus 71 and wire 105 to the other termi otthe battery 100. Current flowingx in the ahovetraced path main ins the energization of the emergency brake controlling; apparatus 71 at all times when the. shoe is in aposition such that the circuit con-, trollc-rs controlled therebyv are in the closed position. It follows therefore that until-2 the shoe 56 contacts with a ramp as 141% the;- energization of the emergency brake, controlling apparatus i'i is maintained. Then; the shoe 56 contacts withanenergizedramp, 8 as 1 the relay 68 isenergized, so that, al though the circuit through the members 6% and 65 for the en'iergency brake controllin apparatus is broken, the other circuit for energizing this apparatus which isi-co'ntrolled by the armature 99 is closed, since the armature 99 is holdin its upper posi-t tion by the energization otthex relay 68,.so that if shoe 56 contacts an energized ramp no action of the emergency-brake controh ling apparatus 71 will tahe place. i i

As the vehicle progresses and itsfirst pair; of wheels and axle ent'er upon the. track circuit section to which the relay 6-.is com nected, that'relay" will be deenergized and 100 its arinatures 4:4 and 35 will tall bygra'vity and make contact with the back contacts thereof, but this cleenergizationtake's placebefore shoe 56 has passed off-'fi'oinsramp 14; in fact, the shoe 56 should that time'bcsomewhat back of: the longitudinal center of the ramp 14' for a reason to be hereinafter more fully explained. Tl s, deenergizaation of relay 6 and the dropping'o'f armature lldoes not, however, deenergizetherelay 66 under theparticular trati'ic conditionsas sumed, where there are no'traiins upon, any portion or" the trackway illustrated, becausethe dropping of armaturei'ee causes a contact of armature 44: with wire 108 .sorthat then acircuit is formed as follows: Gne' terminal of secondary portion v24; wire: 39," armature 36, wire 108, armature-4t in its lower position, wire? 2, circuit c'ontrollerltft in the-closed position, wire 73, ramp 14, shoe 56, wires 74: and 109, armatureSS, wires-110' and Z'Y', relay 66,wi'res 78 and-79, journal box 53', mess, wheel50, raill, wirer30 and, secondary portion to-the ot-lierterniinal of: secondary portion 241. The circuit justl' traced allows the tullpotentiah oiatliei twio secondary portions, 23 a nd 24c, toL' be tcreated between theramp l tfa d the i.-'ail;1-,.so;th a the" relay maintained energizedi and so the relay 67 maintained ven ci'gizetlrand the 139 armature 89 is held in its upper position and no change in the brake controlling apparatus takes place. It should also be noticed that the circuit last traced did not include wire and impedance 7 6, because due to the fact that relay 67 was energized when the circuit traced was formed, the relay armature 88 was in the upper position, as shown, and, therefore, formed a shunt around the impedance 76, so that, although the number of secondary coils included in the circuit were less than when the shoe 56 first struck the ramp, nevertheless due to the fact that the impedance 76 is cut out of the circuit, the voltage is suflicient to cause a suflicient flow of current through relay 66 to maintain it energized.

Not only would current flow through the relay 66 after the wheels of the vehicle had passed upon the section to which the relay 6 is connected, but it would also flow through the relay 68 in a circuit as follows: One terminal of the secondary portion 24, wire 39, armature 36, wire 108, armature 44, wire 72, circuit controller 47 in the closed position, wire 73, ramp 14, shoe 56, wires 74, 75 and 94, impedance 95, wire 96, relay 68, wires 97 and 79, journal box 53, axle 52, wheel 50, rail 1, wire 30 and secondary portion 23 to the other terminal of secondary portion 24. Current flowing in the above traced path would maintain the energization of relay 68 and so maintains armature 99 in the upper position, as shown, so that 5 the emergency brake controlling apparatus 71 would be maintained energized so that there would be no effect upon the movement of the train.

The circuit of relay 68 has been hereinbefore traced. as including wires 116, armature 117 and wire 118,.but as soon as relay 66 is energized the armature 117 is raised to the upper position, as shown, so that all of the current which reaches relay 68 would have to flow through impedance 95, thereby decreasing the flow of current in the circuit, including relay 68, so as to prevent unnecessary waste of energy and to enable relay 66 to get the greater share.

From the foregoing it can be seen that when the vehicle passes the ramp at the en trance to a block, under proceed traffic conditions, when neither that par ticular block or the next block in advance is occupied by another train, the train controlling mechanism 70 is maintained in its normal ineffective condition, and the emergency brake controlling apparatus 71 is also maintained in its normal ineffective condition. As the contact shoe 56 of the vehicle leaves engagement with the ramp 14, the shoe is permitted to be moved downward by the spring 58- far enough to bring the members 60, 62 and 64 into electrical contactwith the members 61, 63 and 65,

before said shoe leaves electrical contact with the ramp 14, so that the maintaining or stick circuits for the relays 67 and 69 are reestablished before the relays 66 and 68 become deenergized.

For the next traffic condition to be considered, assume that the vehicle in question approaches the ramp 14, moving in the direction indicated by the arrow A, while another train is upon the rails of the track circuit section to which the track relay 7 is connected. When the contact shoe 56 en gages with the ramp 14, the high voltage energizing circuits hereinbefore traced and cxplainedfwill be formed through the relays 66 and 68 in the same way as previously pointed out, and will act to keep the train controlling mechanism 70 and the emergency brake controlling apparatus 71 energized; but before the shoe 56 leaves engagement with the ramp 14, the first pair of wheels and axle of the vehicle enters the track circuit section to which the track relay 6 is connected, thereupon causing the armature 44 of said relay 6 to move to the lower position and establish contact with the wire 108. Since the block or track section to which the track relay 7 is connected, is now assumed to be occupied by another train, the armature 36 of said track relay 7 is in its lower position, so that, with the armature 44 in contact with the wire 108, and the armature 36 in the lower position, the voltage available for causing current to flow through the relays 66 and 68 on the vehicle is merely that between the terminals of the secondary portion 23, and this voltage, which is conven iently termed low voltage, is not sufficient, even with the shunt established around the impedance 76 by the armature 88, to maintain the energization of the relay 66. sequently, while the shoe 56 is stillin engagement with the ramp 14, the relay 66 is deenergized; and the relay 67 in turn will also be deenergized, because its stick circuit hereinbefore traced is broken at themembers 62 and 63 of the contact shoe. VV-hen the relay 67 is deenergized, its armature 87 drops and opens a break in the stick circuit for said relay 67, so that although the memhere 62 and 63 contact witheach other when the shoe 56 leaves engagement with the ramp 14, the coil 67 is not energized. Also, when the relay 67 is deenergized, its armature 88 breaks the shunt around the impedance 76, for the purpose pointed out more fully hereinafter. Also, when the relay 67 is deenergized, the armature 89 thereof drops and interrupts the circuit which normally energizes the train controlling mechanism 70, thereby setting this mechanism into operation and rendering it active to control the movement of the vehicle in some appropriate way as it progresses. The exact form of control exerted by the mechanism 70 on the Con- I vehicle is not-iniaterial to this. invention, "although this inec ianisin preferably of some suitable :typ'c whichacts gradually to require the vehicle to reduce its speed as it r gresses :so as to avoid a train ahead.

The difference of potential created by the as shown; and in this Way, the emergency bi'ake controlling apparatus 71 is not decnergize'dand will not, therefore, in any :Way

control the movement of the train.

From the foregoing it can be seen that vhenth'e vehicle passes a ramp, as the ramp li at the entrance to the block, when the nextblock in advance is occupied by'another train, the train controlling mechanism 70 is setiuto operation, while the emergency brake controlling apparatus 71 is still mainthe relay 69 is deenei gized hythe engagetained in its normal inactive conditioni Assiuning that the vehicle, after having hadL its train controlling mechanism ,70' set into operation, asdcscribed, when it passes the ramp 14, continues through the block it has just entered, until it reaches the ramp- 15; and further assume that during the time required for the vehicle to reach the ramp 15, the train formerly assumed to occupy the block to which the track relay 7 is connected, has in the meantime moved on entirely into the next block. Under this assumed condition the track relay 7 is energized, and its armature is in the upper position, so that a high difference of potential, equivalent to the entire voltage of the secondaryportions 23, 2e and 25, is established between the ramp 15 and the track rail 1-. When the.

shoe of the vehicle in question engages the ramp 15, the high voltage a'ppliedto.

this ramp causes sufiicientcurrent to flow through the relay 66,"even with the 1mpedance 76 included in series with said relay, so that the armatures of the relay 66 are raised. The raising of the armature 80 of the relay (36 energizes the coil 67 of the relay 6? and restores the armatures 87, 88 and of said relay 6? to the upper position,

thereby re-applyin energy to the train con-. As the vehicle 111 e: trolling mechanism 70. p H qrestion progresses and enters the block to which the track relay '7 is connected, the,

train controlling mechanism 70 will be again set into ope 'ation by reasonof the fact that a train occupies the next block in advance to which the track relay 8 is connected, .in the same way as herein'hetore described,

Assume that the velucle in question, after having its train controllingmechanism setinto operation when ,it passed the ramp 14,

continues its n'iov'ement and reaches the ramp 15i and vturther assu1'ne that the train torinerly assumed to occupy the bloelcto which? collision with the thextrack relay 7 isrconnected still remains :in thishlock. Under these "conditions the track ;relay 7 is deenergizedand its armature 45 is in the lower position, so, that the voltageiapplied to the ramp 15 is either 1116- :diuin or 101V? voltage, cdepending upon Whether aor n'oit th'eblocl'r to which the relay 8 is connected is occupied. In any event,

its armatures; and consequently, the-train;

controlling, mechanism .70; is maintained deenerg-ized and cont nuesto b etiect vetocontrol the movement of the vehicle. The

mfetliinn or low voltage applied to the ramp 15 is, however, sufficient to energize the re l c'iy GSandhold thearmatures 98aj1d 99 in their upperposition inspite of the fact that the train aheadhas moved entirely into the next block in advance of the block it formerly occupied.

I It the train ahead has not advanced, however, the vmechanism 70 Wlll remain in its active condition, Wh1le the emer ency brake controlling apparatus 71 D will not be affected in either case.

If thetrain having relays 66, 67 and 68 on it deenergized approached the ramp 14 moving in the direction of thearrovv A and its. shoe contacted with ramp 14: at a timefwhen circuit controller 417 Wasopened, either manually or by any desired] means, then there would be ,no potential difference between ramp 1 1 and the rail 1; consequently relay66' would not be energized and relay *67 W0111Cl not; bel'energized, and, consequently, the brake controlling means/7O would he de-energizd a ud ivould gact infany desired manner to con trol or regulate the movement of the vehicle, but in addition the emergency brake controlling apparatus 71 ,WbultlttlSU be deenergized, that, is, an absolute stop would be' effected, because the 'contactof shoe 56 with amp 14 would break contact betiveen v the members and '65 [so that the circuit; gher-e'inb fore traced, includ- 111g the source ,o fcurrent 100, "the emer ency bers and 61 and so break the stick circuit of relay 69, so that as relay 68 is not at that tEime energized the armatures 98 and 99 would all.

It should be understood that the circuit of emergency brake controlling apparatus 71 would only be broken in regular practice by the total deene-rgization of the ramp next ahead in the direction of traffic from a ramp between which and a rail a high followed by a low difference of potential exists so that the train approaching the totally deenergized ramp would be moving under the control of the deenergized train controlling mechanism 7 0 so that its speed would necessarily be so low that upon a deenergization of the emergency brake controlling apparatus 71 the train would be stopped before the shoe left the ramp and would remain there until a difference of potential were created between the ramp and the rail.

From the above description it will be seen that if a car equipped as hereinbefore described approaches the first ramp of a portion of trackway constructed and connected as hereinbefore described it may find five different conditions as regards difference of potential between the first ramp and a track rail, to wit: First, a high difference of potential followed by a medium difference of potential between the ramp and a track rail; second, a high difference of potential followed by a low difference of potential; third, a medium difference of potential; fourth, a low difference of potential; fifth, no difference of potential.

lVhen a vehicle equipped with the parts and circuits as hereinbefore described approaches a ramp with all of its relays, except 66 and 68, energized, then when it contacts with the ramp, if a high difference of potential, followed by a medium difierence of potential, exists between the ramp and a track rail no control of the movement of the train would be caused by devices 70 or 71; if a high followed by a low difference of po tential, or a low difference of potential, exists between the ramp and a track rail, then the movement of the train will be controlled by device 70 only; ifno difference of poten the track rail a medium difference of poten-' tial existedwith relay 67 energized, because the precedmg ramp in regular operation would have deenergized relay 67. To i11u$ trate, medium voltage is supplied to a ramp, as the ramp 15, only when the track relay, as the track relay 7, of the corresponding block is deenergized; and when such conditions exist, the vehicle approaching the ramp 15 will have had its train controlling mechamsm 70 set into operation at the ramp 14 next in the rear. If the relay 67 were energized'when the shoe 56 engages a ramp between which and the rail a medium difference of potential existed the relay 66 would be energized because impedance 76 under such a condition would be shunted because of the fact that relay 67 was energized, consequently the medium difference of potential would be sulficient to so energize relay 66 that its arma tures would be raised and consequently relay 67 would be maintained energized and the train would proceed uninfluenced by device 70, but this condition could only occur due to an irregularity. If relay 67 were deenergized when the train encountered a ramp between which and a rail a medium difference of po tential existed, then relay 66 would not be energized because it would then have impedance 76 in series with it, consequently the train would have to proceed under control of 70.

The greater portion of the ramps, as, 14, 15 and 16, is placed ahead of the insulating joints 8, because it requires a longer ll1t6fval of time to deenergize the relays on the car than it takes to energize them. In the previous description will be found cases where the contact of a shoe with a ramp causes an energization of some of the relays followed by a deenergization before the shoe has left the ramp and because of the presence of tlieshoe on the ramp.

Although I have particularly described the construction of one physical embodiment of my invention, and explained the -operation and principle thereof; nevertheless, I desire to have it understood that the form selected is merely illustrative, but does not exhaust the possible physical embodiments of the idea of means underlying my invcntion.

Vhat I claim as new and desire to secure bv Letters Patent of the United States, is

1. In an automatic train control system, 111 combination: a trackway divided into track circuit sections vand having a movable vehicle thereon; a movable contact member positioned on the movable vehicle; means governed by the track circuit sections for creating a high, medium or low difference of potential between the ramp and a rail of the trackway; a partial circuit on said vehicle including an impedance and a relay; means for closing said partial circuit by the contact of thecontact member with the ramp and energizing said relay and causing it to lift itsarmature when a high difference of potential exists between, the ramp and a, rail of" menses the track; a seeondrelay; means governed by said first relay for energizing said second relay; means-including a circuit controller governed by said movable contact member for maintaining said second relay energized; means g-(Werned by said second relay itor forming a shunt path about saidimpedance whereby the medium difference of potential between the ramp and a rail will when the contact member contacts a rampenergiae'the first nientioned relay suiiiciently to cause it to raise its armature;

means governed by the second mentioned relay for controlling the movable vehicle; and means for governingthe vehicle controlled by the low (litterence of potential.

2. In an automatic train control systen'i, in combination: a tr-aclcu'ay divided into track circuit sections each including a transi 1 i i JO 1L1 L a .i liting device; 1*311 's ored t the 61 trance to each track circuit section; means "tor-creating a difference of electrical potential or high, medium or low value; mea s governed by the translating device of a section at the entrance to v-riiich a ramp is positioned to create a high difl erence oi potential between that ramp and a rail of the trackivay means governed by the translat ing device of the section at the entrance to which a ramp is positioned and the trans lating device of the track circuit section in advance to create a medium or low difference or potential between that ramp and a rail of the track; and means responsive selectively to said di'tl'erences of potential for controlling a movable vehicle. 1

o. 1.11 an automatic bl. control system, in combination: a vehicle; brake controlling hieans "for controlling the movement of said vehicle and set into operation when deenergized; a circuitior normally energizing said brake controlling means; a relay for controlling said circuit; a circuit controller for governing said relay; a circuit for maintaining said means energized independently oi the operation of said relay; and means contact rails; a circuit controller op erated said Contact shoe and opened when said shoe is operated by engagement with one of said contact rails, said circuit coir lie, in combination trolle-r being. included Linsaid/normally:closed circuit; a normally closed circuit "for maintaming said mechanism energized independently .of the operation of said relay; and

means governed: by said contact shoe fo'r opening said last mentioned circuit when said shoe engages one 0t said conta c-tziai'ls.

5. In an automatic train control systeinyin combination: a trees; a vehicle-adaptedto travel over said track;mechan sm i'or governing the .inoveinent "of said vehicle; alciscuit for governing said mechanism; a circuit controller included in said circuit; arelay for controlling saidcircuit controller; a normally closed circuit for energizing said relay; a circuit control-ling devicecarried.by said vehicle for inteirupting said nonn'ra-lly closed circuit; tra-tlic GOHtlOllGCl'IneaD'S 10- seated at intervals alongsaid track to'r opcrating said circuit control-ling device; an-

other relay tor controlling saidv circuit controller; and means controlled by saidsxlast mentioned means for energizing said ;an other relay. 1

6. In an automatic train control system, the combination with a vehicle and a track therefor, of impulse transmitting devices located at intervals along the track and adapted to assume dill'erent controllingconditions, one or more of said devices being capable of assuming an additional distinctive controlling condition, means for auto matically governing the controlling conditions of all of said devices in accordance with trailic conditions in advance, n'ian'ually controlled means for causing the distinctive controlling condition thegparticular devices, automatic train control appa ratus on the vehicle governed by the controlling conditions of said devices and adapted to gradually regulate the progress of the vehicle,' and separate automatic train control mechanism on the vehicle governed by the distinctive control-ling condition tot the particular devices and adapted to lll'lll'lQ- diately arrest the movement of the vehicle.

' '7. In a system for i-otecting irail i'vay itrata railroad track; a vehicle adapted to travel over said track;

separate :traf'rlc protecting apparatus and mechanism having operating conditions corresponding to the occasions Where the vehicle should proceed cautiously or should stop, respectively; means on the vehicle for controlling said apparatus and responsive to different voltages; other means for COIllllOlling said mechanism which operates to set the mechanisn'i into operation when no voltage is applied to it; devices carried by the vehicleand located atxintervals along the track in cooperative relation for applying difierent voltagesrto said first mentioned means in accordance with the trellis conditions along the track: and manually conice trolled means for controlling said devices to cut off the supply of voltage to said second mentioned other means.

8. In a system for protecting railway traffic, in combination: a railroad track; a vehicle adapted to travel over said track; separate traflic protecting apparatus and mechanism having operating conditions corresponding to the occasions where the vehicle should proceed cautiously or should stop, respectively; said mechanism and said apparatus both having a tendency to assume their active condition; means energized by a source of current carried by the vehicle for maintaining said mechanism and said apparatus in their inactive condition; other means selectively responsive to potential differences of' different intensities for maintaining said apparatus and said mechanism in their inactive condition; and means for energizing saidlast mentioned means by a current distinctive in character from the current derived from said source and for simultaneously rendering said first men tioned means ineffective.

9. In a system for protecting railway traffic, in combination: a track divided into track circuit sections; a contact rail associated with each track section; partial circuits associated with each contact rail and terminating at that contact rail and a track rail of the track; means controlled by each track circuit section for energizing said corresponding partial circuits with currents of different intensities according to whether or not the corresponding track circuit section is occupied; and manually controlled means asssociated with a contact rail'for interrupting all of the partial circuits associated therewith.

10. In a system for protecting railway traflic, in combination a vehicle; traffic pro tecting apparatus carried by the vehicle; two relays carried by the vehicle for controlling said apparatus; said relays being connected in parallel; means included in the circuit for one of said relays for increasing the opposition to the flow of current therein; a shunt for said means; and means for closing said shunt when the other relay is deenergized.

11. In an auton'iatic train control system, the combination with a vehicle and a track therefor divided into blocks, of an impulse transmitting device associated with each block and adapted to assume different con trolling conditions, sources of electrical energy of different characteristics for produo ing the different controlling conditions of said devices, circuits for controlling the 0011- nection between said sources and each device, traffic controlled means for governing impulse transmitting devices from their respective sources.

12. In an automatic train control system, the combination with a railway track, of an impulse device associated therewith and adapted to assume difierent controlling conditions, circuits for supplying electrical energy of different characteristics to said impulse device to produce the different con trolling conditions thereof; traflic controlled means for governing said circuits automatically, said. circuits regardless of traffic conditions normally supplying some energy to the impulse device, and manually controlled means for interrupting all of said circuits and thereby deprive said impulse device of all electrical energy;

13. In an automatic train control system, the combination with a vehicle and a track therefor, of separate automatic traific protecting apparatus and automatic train control mechanism on the vehicle for governing the movement thereof according to whether the vehicle should proceed cautiously or stop respectively, said apparatus being responsive to variations in the amount of current supplied thereto, said mechanism being rendered effective by the failure to supply current thereto, impulse transmitting means comprising elements partly on the vehicle and partly along the track for governing the amount of current supplied to said apparatus and mechanism in accordance with traffic conditions, and manually controlled means for cutting off all supply of current to said apparatus and mechanism at predetermined control points along the track.

14. In an automatic train control system, the combination with a track divided into blocks each having a track relay, of a ramp located adjacent to the entrance end of each block, a partial circuit for each ramp including a high voltage source of current and the front point of the track relay of the correspondingblock, a second partial circuit for each ramp including a medium source of current, a back point of the track relay of the corresponding block and the front point of the track relay of the next block in advance of the corresponding block, and a third partial circuit for each ramp including a low voltage source of current, the back point of the track relay of the corresponding block and the back point of the track relay of the block next in advance of the corresponding block.

15. In an automatic train control system, the combination with a track divided into blocks each having a track circuit, of an impulse device associated with each block, partial circuits for each impulse device including sources of current of different voltages and controlled by the track circuit of theblocl; next in advance of the corresponding block, another partial circuit controlled solely by the tIfiClicircuit of the.

corresponding block, and means controlled by the track circuit of each block. for alternately connecting the corresponding ramp;

to the first mentioned partial circuits and said another partial circuit.

16. In. an automatic train control system, the combination with a. track divided into blocks-,of an impulse device associated: Witheach block, a circuit for. controlling. each impulsedevice, means responsive to the presence of a train in the. corresponding block for controlling-said circuit, tWo other circuits for controlling each impulse device having sources of current of d-rllerent vol-tages included therein, means responsive to rate mechanism for immediately arresting,

the movement of the vehicle, impulse transmitting means along. the. track and controlled. in accordance With tralric conditions for governing said: apparatus, and manur ally controlled means associated with; one or more of the-impulse transmitting. means for governing said mechanism.

18. In an automatic train control system, the combination with a vehicle and a track therefor, of means on. the vehicle for regulat ing, the speed thereol from point to point along. the track, tra'lliccontrolled impulse devices at said points for governing said means, one or more particular impulse devices being capable of assuming an additionaldistinctive controlling condition, and means on the vehicle governed by the dis tinctive controlling condition. of. said particular impulse devices for immediately arresting the movement of the vehicle independently otthe first mentioned means.

19. In an automatic train control system for railroads, in. combination: a railroad track divided into blocks; a vehicle adapted to travel over said track: an impulse device at the entrance to ca 1h block adapted to transmit controlling impulses to a passing.

vehicleboth prior and subsequent to its entrance into. that block; control circuits and sources of current associated With each impulse device and controlled by the track relays of the corresponding block and the next block in advance, said control. circuits cansing an impulse device to be energizediby the current of one characterlstlc When the c0rresponding-block is not occupied, to be energized by current of another characteristic When said corresponding block is occupied and the next block in. advance is not occupied, and to be deenergized When both of saidblocks are occupied; and train controlv apparatus on the vehicle selectively responsivo to the different energized and. deenergizedconditions of said impulse devices.

20. In an automatic train control system for railroads, in combination: a railroad track divided intoblocks; a vehicle adaptedto travel over. said track; automatic trafiic protecting apparatus on the vehicle; control means for governing; said apparatus hich is selectively responsive in dillerent Ways to currents of: two dillerent characteristics dependent'upon Whether or'not said apparatus is their active or inactive; and means for supplying current from the track to said controlling means at the entrance to each block, the characteristic of such. current supplied; by said means being automatically controlled in accordance with the. presence or absence of a vehicle in the corresponding block.

21. In an automatic train control system for railroads, in combination: a railroad track divided into blocks; a vehicle adapted totravel over said track; an impulse device associated with each block; two sources of currentonthe track of. dili'erent voltage for each impulse device; circuits including said sources-for energizing each impulse device, one circuit being normally closed; anduneans for shifting the control of each impulse device from said normally closed circuit to the other circuit as the vehicle passes the corresponding impulse device.

22. In an automatic train control system for railroads, in combination: a vehicle} mechanism for controlling. the movement of the vhicle; a normally energized. relay for governing SfLlCl' mechanismya normally deenergizcd relay for governing said first mentioned relay; a circuitincludingv said normally deenergized relay; and means for increasing the opposition to the flow of current in said circuit without actually interrupting it upon deenergization of said first mentioned normally energized relay.

In an automatic train control system for railroads. in combination: a track di vided into blocks lnving tracl relays; a vehicle adapted to travel over said tract; tra'liic protecting mechanism on the vehicle responsive to electric currents of dilleren: characteristics; an impulse device at the entrance to each block; two circuits for controlling, each impulse device and including sources of current of di'flerent electrical characteristics; and means controlled by the track relay of the corresponding block for closing a break in one circuit when said block is not occupied and for closing a break in the other circuit when said block is occupied. V

In a system for protecting railway traffic, in combination: a vehicle; automatic traiiic protecting apparatus carried by said vehicle; a relay for controlling said apparatus; a second relay responsive to alternating current i or governing the first relay; a contact shoe carried by said vehicle; two partial circuits of dii'iercnt impedance for governing said second relay and terminating at said contact shoe and at the wheels of said vehicle; and n'ioans governed by said first relay for selectively controlling said partial circuits.

25. In a systen'i for protecting-railway tratiic, in combination: a traclc divided into track circuit sections: a contact rail asso ciat-ed with each tracl: section; two partial circuits associated with each contact rail for establishing diiierences of: potential of diiterent intensities between that contact rail and a track rail, said partial circuits being; selectively controlled by the corresponding track section according to whether or not that track circuit section is occupied, oncoi said partial circuits being also controlled by the next tracl: circuit section in advance and being closed only when that next track section is unoccupied.

26. In a system for protecting railway bltlillti, in combination: track rails'constituting a railroad track, said track being divided in" insulating joints into track sections; a source ot current and a relay associated with each 0. mid sections 1 (on titutinn a normally closed track circuit; contact rails associated with said tract: circuit ,crtions and extending along said track on both sides oi the insulating joint t tli eutrauce to the corresponding track r. i'

it section; a vehicle adaptedto travel on said traclr; a con-- tact shoe carried by said vehicle and arranged to engage said contact rails; and automatic traitic protecting apparatus on said vehicle governed by the COOPGItLl'lOD of sztid. cont-act shoes and said contact rails 27. In an automatic train control system, a partial circuit on a vehicle, a relay included in said partial circuit, means con trolled by said relay for modifying the electrical characteristics of the partial circuit and thereby rendering the energize! ion oi the relay dependent upon the characteristics of the electrical energy supplied to said partial circuit in accordance with the existing condition of the relay and means responsive to tratl'ic conditions along the track for supplying electrical energy of different characteristics to the partial circuit in accordance with said traiiic conditions.

28. In an automatic train control system, a partial circuit on a vehicle, an electroresponsive device included in said circuit, means controlled by said device for varying the opposition to the flow oi current in said partial circuit, and trafiic controlled means along the track for supplying diiierent voltages to the partial circuit on the vehicle in accordance with trafiic conditions ahead.

29. In an automatic train control system, in combination: a track divided into blocks each having a track relay; an impulse device located near theentrance end of each block and disposed in position tie-cooperate with an impulse device on a'passing vehicle both prior and subsequent to the entrance of that vehicle into the corresponding'block said impulse devices along the track being adapted to have different controlling conditions; a circuit controlled by the track relay of the block immediately in advance of an impulse device for determining the occurrence of one controlling condition thereof; and a second circuit controlled by the track relay of the second block in advance of the impulse device for determining the occurrence of another, controlling condition of said impulse device.

30. In an automatic train control system, in combination: a track divided into blocks each having a track relay; a contact rail located near the entrance end of each block; a partial circuit associated with each contact rail and including the front point of the track relay of the corresponding block, said partial circuit including a source of current; and a second partial circuit-associated with each contact rail and including the back point of the track relay of the corresponding block and a frontpoint of the track relay of the next block in advance, said second partial circuit including a source of current of lower voltage thanthe first mentioned source.

31. In an automatic train control system for railroads having tracks divided into blocks each provided with a track relay, in combination: an impulse device at the entrance to each block arranged to transmit impulses to a passing vehicle both prior and subsequent to its entrance into that block; a control circuit for energizing each impulse device including a source of high voltage and gOVQlllGd by thetrack relay ot the corresponding block; a second control circuit for energizing each impulse device including a source oi low voltage and having its continuity governed by the track relays ot the correspoinling block and the next block in advance; automatic train control apparatus on the vehicle adapted to be influenced distinctively by the different energized or deenergized conditions of each impulse device,

said ap 'iaratus being restored to its lililtltlYe condition by the influence of an impulse device supplied 'witlrhigh' voltage'g'being maintained but not restored-by the influence of a device supplied withlow voltage, and being set into operation by adeenergiz'ed impulse device.

32. In an automatic train controlsyst'em, incombination: a track divided into blocks; an impulse device located near the entrance end'ofeach' block; two controlling circuits for each impiilse device having sources of current included therein which have different voltagesfone ofth'e'cont'rolling circuits being closed when the corresponding block is not occupied, andthe othercontrolling circuit being closedwhen the corresponding block is occupied and thenext block in advance is not occupied.

3. In an automatic train controlsyst'em, in combination: a track divided into blocks, an impulse device associated with each block; two controlling circuits for governing the controlling condition of each impulse device; the continuity of one controlling circuit being interrupted when the block corresponding to the associated impulse device is occupied, the continuity of the other controlling circuit being interrupted when the block next in advance of the block corre sponding to the associated impulse devlce is occupied; and means associated wlth each block and responsive to the presence of a train thereon for selectively controlling the connection between the corresponding 1mpulse device and its controlling circuits.

34:. In an automatic train control system,

in combination: a track divided into blocks; an impulse device associated with each block; two controlling circuits for each impulse device having their continuity dependent upon the presence or absence of a train in the corresponding block and the next block in advance respectively; and means governed by a passing train for rendering the controlling circuits for an impulse device successively effective to determine the controlllng condition of that impulse device.

85. In an automatic train control system, in combination: a track divided into blocks; means comprising cooperating elements partly on the vehicle and partly along the track for transmitting controlling impulses to the vehicle as it reaches the entrance to each block, said elements along the track being capable of assuming different controlling conditions; means for rendering one controlling condition of the trackway elements dependent upon the presence or absence of a train in the corresponding block; and means for rendering another controlling condition of the trackway elements depend out upon the presence or absence of a train in the block next in advance of the corresponding block, said means being autoniatically rendered effective in succession during the passage of the vehicle.

-37. Inan automatic train controlsystein, in: combination: a track'divided into-blocks each havinga track relay; 'animpulse device at the entrance 'to eaclrblock and arranged to transmit impulses to a: passing vehicle both prior and subsequent to its entrance into that block; a circuit for energizing each impulse device by current of one characteristic and including a front contact of the track relay of the corresponding block; and a second circuit for energizing each impulse device by current of another characteristic and including a back contact of the track relay of the corresponding block and a front contact of the track relay of the block next in advance.

38. In an automatic train control system for railroads having tracks divided into blocks each having a track relay, in combination: an impulse device at the entrance to each block arranged to transmit impulses to a passing vehicle both prior and subsequent to its entrance into that block; trackway circuits and sources of current for placing each impulse device in one controlling condition when the corresponding block is not occupied, in a second controlling condition when the corresponding block is occupied and the next block in advance is not occupied, and a third controlling condition when both of said blocks are occupied; and automatic train control apparatus on the vehicle responsive to the different controlling conditions of said impulse devices and adapted to be restored to its inactive condition by the first controlling condition, maintained but not restored by the second, and set into operation by the third.

39. In an automatic train control system for railroads having tracks divided into blocks each havinga track relay, in combination: automatic train control apparatus on a vehicle adapted under the influence of an impulse of a predetermined character to remain in the same active or inactive con dition then existing; and trackway circuits and impulse transmitting devices including means for transmitting to the vehicle such impulse of predetermined character at the entrance to each block when the next block in advance is not occupied, together with means for causing said train control apparatus to be restored to its inactive condition at the entrance to each unoccupied block, these means acting in succession to influence the apparatus on a passing vehicle as it enters each block.

40. In an automatic train control system for railroads having tracks divided into blocks, incombination: train control apparatus on a. vehicle included in a normally closed circuit and inactive when energized; controlling means responsive to currents of different voltages for governing said normally closed circuit; and means for establishing communication between the. vehicle and the track at the entrance to each block and adapted to supply currents of different voltages to said control means successively as the vehicle passes each impulse devic deand the block next in advance, whereby said train control apparatus will be restored at the entranceto each unoccupied block and Will be set into operation or maintained inactive respectively depending upon the presence or absence of a train in the next lock in advance.

tl. In combination a railway track a vehiclethereon, ramps on said track energized by a source of alternating current, a shoe on said vehicle engaging said ramps, a closed circuit energized by direct current on said vehicle and interrupted by said shoe an alternating current relay responding to the current in said ramps, said relay When energized, closing the circuit interrupted by said shoe.

' W'INTHROP K. HOWE; 

